Brother HL-2700CN Series, Service Manual, Page: 65 / 377

IV-12
3 Developing
Developing Process means that an electrostatic latent image on OPC belt is made
visible with toner.
(1) Structure of Toner Cartridge PU (Refer to Fig.4-8 & 4.14.)
i) Toner cartridge PU is located as shown in Fig.4-8.
ii) Four toner cartridges are made available from the top to bottom in the order of
specified color as black, yellow, magenta and cyan.
iii) Each color toner is loaded in the corresponding toner cartridge PU.
(2) Process of Developing (Refer to Fig.4-8, 4-14, 4-15, and 4-16)
i) Toner adheres to the Dev.roller of toner cartridge PU.
Developing is processed by this Dev.roller contacting the OPC belt surface.
ii) Dev.roller has been biased to the potential -DBV(V). Fig.4-15 describes the
relationship established between the potential of toner, the potential -V
0
(V) at
the non-exposed area of OPC belt and the potential -VR(V) at the exposed
area of OPC belt.
iii) Developing is processed by the toner adhering to the OPC belt due to the
attraction between the potential of toner and the potential -VR(V) at the
exposed area of OPC belt. (Toner image is formed (visible) on the OPC belt.)
iv) On the other hand, no development takes place at the non-exposed area
because the potential of toner and that of OPC belt is identical pole and
therefore repels each other.